


Nox AU: Of Myths, Merfolk, and Maybe Marriage Contracts

by SecretEnigma



Series: Nox-verse [2]
Category: Final Fantasy XV
Genre: Alternate Universe - Fantasy, Alternate Universe - Merpeople, Always a Girl Nyx Ulric, Don't copy to another site, F/M, Fem!Nyx Ulric - Freeform, Gen, Genderbent Nyx Ulric, Good Ardyn Izunia, He Wants His Human Legs Back Please, He Was Not Always a Merman, How do you write romance, I don't know, Imma do it anyway, Less Plot Than I Usually Go For, Leviathan Who Brought Nox To This AU, Mer AU, Merpeople, Nox is a Merman, Nyx is a Pirate, Pirates, Shan't, There Are Never Enough Mer AUs, What if FF15 But Swashbuckling, Why Did I Write This?
Language: English
Status: Completed
Published: 2020-06-25
Updated: 2020-06-25
Packaged: 2021-03-04 00:07:50
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,136
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24904333
Author URL: https://archiveofourown.org/users/SecretEnigma/pseuds/SecretEnigma
Summary: When Nyx Ulric first left her jungle home of Galahd to become a pirate and fight back against Niflheim's encroachments in Galahdian waters, she was pretty sure the ocean was going to kill her at some point. Leviathan's temper was unpredictable after all, and she was no Furia, raised on the art of sails and ships and not falling overboard in storms.She just didn't expect it to be death by a merman- a member of a race thought hunted to extinction at the beginning of Niflheim's conquests over a hundred years ago. But all the legends say that death by bewitching song and ravenous teeth is all that awaits a sailor that meets one of the merfolk in the open sea, so that has to be what this merman wants with her....Right?
Relationships: Noctis Lucis Caelum/Nyx Ulric
Series: Nox-verse [2]
Series URL: https://archiveofourown.org/series/1556734
Comments: 30
Kudos: 174





	Nox AU: Of Myths, Merfolk, and Maybe Marriage Contracts

When you rode the waves for a living, you had to make peace with the fact that Leviathan’s mercy came in many strange and often dangerous forms, and that even that strange form of mercy might be revoked at any moment. Death could come from any angle and in any form, and if you dedicated your life to the waves, you had to accept that someday the waves would come to claim it.

That didn’t mean, of course, that Nyx had expected it to end **quite** like this.

The fight with the blasted Nif fleet had been expected, with all the raids she and the other ships in the Galahdian Flotilla —built mostly by Furia and Tibiae, but crewed by all the Clans at this point in an effort to free their home—, it had been a given that the Nifs would send their navy after them, and that someday they’d be caught. The fight had been bloody and brutal, but they had eventually pulled away, riding the edge of a storm’s teeth in ways that most of the Niflheim fleet wouldn’t dare. But one ship had followed, one bearing the signature red lion of the Tummelt family, riding the storm’s fangs almost as well as hers had, and in the following chaos that was a ship to ship battle in the middle of the Storm-Father’s wrath, Nyx had gotten knocked overboard and into the churning waters, so fast and sudden she doubted even Lib had had time to notice until it was far too late.

And that, Nyx had thought as she’d fought the waters until she was too tired to, was going to be that. She was going to drown in throws of the Tidemother’s furious dance with Ramuh. She could only hope that the ship and the rest of her friends got away unharmed.

But then, somehow, with a lot of luck and a chunk of broken wood the size of a small table, she had survived the storm.

There had been no signs of either ship come morning. She prayed that meant they were safely away and not sunk into the waves, but no matter their fate, Nyx had to worry about her own situation. Namely, drifting at sea on a piece of wood just barely large enough to hold her body without sinking, with no drinkable water but the little canteen that had somehow managed to cling to her belt through the storm and a hot sun beating down on her with no shade.

Nyx squinted up at the sky, running a dry tongue over cracked lips as she considered her plight. She’d been drifting for five days now. Even rationing as strictly as possible, she’d run out of water in her canteen two days ago, and she hadn’t had food since the morning before the _Stormheart_ had nearly gotten caught by the Niflheim fleet.

She’d expected to die faster than this, honestly. Either in battle or by drowning. Ulrics had never been a particularly seafaring clan for a reason after all, they preferred the jungles, excelled in places where climbing and acrobatics and stealth were key rather than sails and rigging and trying not to get sick standing on a deck that was always moving. Yet here she was, on driftwood, baking and starving and dehydrating all at once without a speck of jungle foliage in sight. Pity. She knew that Galahdian souls were welcomed by the waves just as much as the Infernian’s Pyre, but she still would have preferred to be laid to rest the **traditional** way for Ulrics —burned in her best clothes, her ashes gathered and scattered to the jungle to stimulate new growth—.

She jerked awake when something underneath her little makeshift raft went “thump” —when had she fallen asleep this was bad—. Nyx propped herself up on her elbows, one hand groping shakily for her remaining kukri —she’d lost the other one during the storm, and oh that burned, but one was better than nothing— as she stared at the waves for signs of life. Another bump, rocking her raft to one side, and a fleeting glimpse of something very large and long and vaguely serpentine diving out of sight. “Great,” she whispered hoarsely, unable to speak louder from lack of water, “just great. Here for lunch big fella?” Another glimpse of the long shadow coming toward her piece of driftwood, looping and careful.

Something slammed **down** onto the raft from the other side and suddenly Nyx was underwater, gagging on the saltwater flooding into her unprepared nose and mouth as she flailed blindly, trying to kick to the surface and swing her kukri at whatever threat had just ambushed her. Her head smacked against the wood of the makeshift raft and Nyx saw stars that quickly turned to desperate starbursts as she accidentally gasped and inhaled more water.

Something grabbed her, pinning her arms to her sides in her vulnerable, distracted moments and she thrashed as hard as she could with her steadily weakening limbs. Her legs kicked against something that felt vaguely like tail, but the things pinning her arms felt almost like clawed hands. Her eyes opened, squinting against the flickering starbursts and the stinging saltwater, trying to get a look at what had her, how to fight it off-.

Blue eyes. Blue eyes the color of the ocean on a clear summer day and wispy black hair twining around bare shoulders speckled with iridescent blue scales.

_Tidesinger. Wavechild._ ** _Merman_** _._ One of Leviathan’s Blessed, the mythical, long lost children of the sea, hunted to extinction by Niflheim decades ago, except **not** because there was one right here and he was more than likely trying to either drown her or **eat** her —all the legends said merfolk lured and ate unwary sailors, a visceral revenge for driving their race to the brink of extinction and beyond— or **both**. The last of her air slipped out her nose in bubbles and blue eyes went wide. There was a blur of movement beneath her and-.

Surface.

**Air**.

Nyx heaved and shuddered, vomiting seawater back into the waves lapping at her shoulders and **probably** on the merman who was still pinning her arms in place. There was a voice murmuring in her ear, soft and nonsensical and chattering like the babble of waves against sand. Oddly soothing for something that belonged to the mythical being who had just tried to kill her. Nyx coughed out the last sea water, gasping greedily through a very sore throat, too tired to struggle for the moment. Instead she went limp, resting her forehead against the water slick, scale-speckled shoulder of the merman. The hands pinning her arms —and also holding her above the water—, flexed slightly and she felt the prickle of claws through her tunic.

_“Daijoubu desu ka?”_ Murmured the voice right by her ear, melodic and so very, very strange and Nyx shuddered.

There was a splash nearby, a sense of **presence** and she forced herself to look.

Red-violet hair and delicate scales running down his cheeks like scarlet tears in the sunlight, a cheerful grin that was pure razor sharp needle teeth.

A second merman. Of course. Lovely.

“I don’t think there’s enough of me for two to share,” she rasped, morbid humor keeping her calm, “not at your sizes.” They were, after all, the size of human beings from their torso’s down, but their tails were **long**. Even above water she could see the silhouette of their tails twisting beneath them, at least six feet of pure muscle and scale and billowing, deceptively delicate looking fins. It would take a lot of energy to use that to maneuver through the waves, and a lot of energy meant a lot of food.

Though if they wanted to eat her, she wasn’t sure why the black-haired one had dragged her to the surface for air.

The two were chattering to each other, fast, rolling speech that made no sense to her. The redhead was oddly cheerful, gesturing and splashing freely as he spoke. The black-haired one —younger one? He looked younger, he looked like a young man of maybe twenty if he’d been human while the redhead looked closer to thirty-five— was snappier, he seemed angry about something. They kept arguing over Nyx’s head for several more minutes while Nyx just- took the opportunity to breathe and get her bearings and maybe try to come up with a plan of escape if these two decided to eat her.

A glance proved her makeshift raft was in too many small pieces to use, probably smashed by whichever merman had knocked her in the water. Which meant her resources for escape was her one kukri still clutched in one hand —a hand still pinned to her side by the black-haired merman— and her own swimming ability.

Who was she kidding, there was no way she was escaping two **merfolk** with those.

The two mermen were still arguing, loud and cheerful on the redhead’s part, loud and annoyed on the black-haired’s part. They were probably arguing over who got to eat her. _I’m about to be eaten merfolk out of vengeance for_ ** _Niflheim’s_** _endless hunts and extermination_. How horribly, morbidly unfair.

“I know I have no say in this,” she mumbled into the shoulder of her captor, “but if you two are debating on who is gonna eat me, then I want it to be the pretty Blue Scales here rather than Red Tears.” The arguing paused and the two mermen looked at her thoughtfully. She wondered if they could understand human languages. She sighed quietly into Blue Scale’s pale shoulder, “Lib is gonna be **so** mad when he finds out about this. He always said my reckless streak would get me a particularly nasty fate.”

Blue Scales eyed her for several seconds, then sighed and chattered something at Red Tears, who gave a noise that sounded distinctly like a cackle. The world tilted and Nyx braced to be dragged underwater-.

She blinked. Blinked again. Raised her head and looked **down** at the merman now lying on his back, floating on the waves with her sprawled on his torso and part of his tail like some kind of clam on an otter’s belly, “Aren’t you gonna at least rip my throat out before settling down for dinner?” Or maybe they liked to eat live prey. Who knows. The legends were all wildly different, only ever agreeing on a few key parts. Blue Scales blinked at her, then slowly let go of one of her arms —not the one with the kukri— and ran his clawed fingers carefully through her salt-crusted hair. He began to hum a strange, otherworldly song and Nyx felt a part of her brain go “oh”. Right. Bewitching usually came before eating. Guess it was a requirement of the process.

…The legends hadn’t been kidding about Leviathan granting her children the most beautiful voices of the four winds and tides. Even **knowing** what he was doing, this was … beautiful. Soothing and soft, wrapping around her like a blanket of pure, warm sound. Nyx contemplated fighting back, but … again. Where would she go? It was either this or drowning when exhaustion finally stopped her from swimming.

Nyx sighed and laid her cheek on his chest, dully counting the hundreds of scars littering his skin and scales as she drifted off to sleep beneath the siren song. _Guess this is how I go out … sorry … Lib…_

Light and dark, sound and silence. Nyx drifted for a long time. Unmoored from reality, only aware of snatches that came and went like dreams. The plick-plock of water dripping from a cave ceiling, the chatter of voices using unknowable words. Something being pushed against her lips —food?—. Then the uncomfortable flicker-memory of vomiting onto stone when she couldn’t stand it.

Lips against hers, coaxing her mouth open, the graze of sharp teeth as a hand gently rubbed her throat to make her swallow.

When she woke up —really woke up, not just drifted to near-consciousness before fading again—, it was to the confusing sight of a cave ceiling, and the even more confusing sensation of being **warm** —and just being alive in general really—. It took her a long moment to remember what had happened, what had **been** happening when she was last conscious. She remembered the merman singing her into oblivion, the surety she was going to be **eaten** , and she jerked the rest of the way awake thanks to the adrenaline that jumped into her system. She tried to sit up, failed to move more than an inch thanks to the iron-strong bands wrapped around her waist. She blinked, craned her head to look down … oh.

This was…

Kind of the opposite of being eaten by a merman.

Blue Scales sighed in his sleep and only now did she register his breath puffing against her neck, slow and steady as the slight push of his chest against her arm. Blue Scales was … cuddling her. In his sleep. Sleeping with her? No, bad implications with that wording, even if it was the literal truth, because Blue Scales was out cold, curled up on a pile of bits of fabric and scraps of furs that was probably supposed to be a bed, his arms wrapped around her, holding her close to him. His uppermost part of his tail was draped over her legs, weighing them down even as the lower part of his tail twitched sluggishly in the water what looked like an underground lake —she’d bet any amount of gil that the water was actually the only human-sized exit into or out of this place, though there had to be **some** kind of other path to the surface since she could smell fresh air—.

Okay so … she was not … not mer-food, apparently. So … what then? Mer-toy? Mer-pet? Mer … girl toy?

She carefully tried to get a better look at the cave and ignore —for now— the bonfire of heat that was the merman curled around her. The cave looked … halfway lived in. Not a proper house at all, but there were strange brightly glowing plant things hanging from the walls and more furs and bits of fabric and old sail spread out almost like carpet on the floor. It looked like a camp really. Though why merfolk would need an above-water camp was a mystery to her.

Unless this was where they kept all of their human … somethings. She was still working out if her being alive and uneaten was actually a good thing.

Blue Scales sighed again and the arms wrapped around her tightened, then relaxed. She shifted her head to look and blue eyes opened sleepily. They locked gazes for several long seconds before Blue Scales realized she was **awake** and he sat up sharply, letting go of her in the process, though his tail was still on her legs, “Ah, um,” the siren of the waves said in **spectacular** articulation. Nyx couldn’t help but laugh at him, because if he was going to do something to her, at least she could make fun of him beforehand —though if he **wasn’t** planning on something … she’d figure that out soon enough—. He blinked at her, then smiled, a lopsided, pointy thing with those teeth of his.

“You-,” her voice cracked and she coughed. The merman shifted, reaching over her to grab a … cup? A cup, and fill it with the water from the lake. He helped her sit up and pushed the cup into her hands, and a tentative sip revealed that, huh, it wasn’t salt water. Sitting up the rest of the way, Nyx looked around better and realized that … yeah, she really was alive. She wasn’t starving to death, she wasn’t eaten, and Blue Scales was watching her with an expression that was astonishingly gentle and … human. He chattered out something that might have been question about how she felt and Nyx grinned at him despite herself, “You saved me. Why?”

Blue Scales blinked, tilted his head and hummed musically before tapping his lips, then his ears, and shaking his head. Nyx worked that out in her head, and assuming it wasn’t merfolk for something totally off the wall, “You don’t know this language?” She pointed to her own lips, then her ears as she said it. Blue Scales gave a hesitant nod.

They looked at each other in awkward silence, then Blue Scales sighed and tapped his hand against his scarred — **severely** scarred, though considering merfolk were supposed to have been driven extinct by Niflheim, scars on a survivor wasn’t unexpected— chest, “Nox.”

Nyx gaped at him for a few seconds, then mumbled, “That’s a **much** more normal and pronounceable name than I was expecting, if I’m honest. Uh,” she tapped her own chest awkwardly, because this guy had not only chosen not to eat her but had saved her life —for now anyway— so a name was only polite right? “Nyx. Nyx Ulric.” Maybe she shouldn’t have included her clan name, he hadn’t, though whether that was because he didn’t have one or because merfolk didn’t **do** clan names was up for debate.

“Nyx,” chirped Nox with surprising confidence and wow did he manage to make her name sound pretty. How did he do that.

Nyx pushed that question out of her head and smiled at him. He smiled back, lopsided and pointy as before and Nyx felt her stomach twist in a way she knew from **several** embarrassing childhood stints of acclimating to hormones. _Oh no,_ she told herself as she looked away sharply, _don’t you dare. Do_ ** _not_** _get a crush on the merman who might still be planning to eat you or something. Even if he probably isn’t since he saved you and introduced himself. And is_ ** _very_** _attractive. And has a_ ** _great_** _singing voice._

A glance at him showed that he was watching her with a furrowed brow and a tilted head and now that she was properly awake and not half-drowned Nyx could fully appreciate how toned he was, lean and tall and not an ounce of fat, with glittering blue scales speckling over his shoulders and upper arms that steadily got thicker down his waist until they turned into his long, sweeping tail.

_Too late,_ she thought distantly to herself, _I have a crush. Whoo boy._ She looked up at his face, where he was watching her in quiet concern, and she laughed to herself, “I’d say ‘thanks’ but I know you don’t understand me.” Then, because she was grateful and reckless and also crushing very, very hard on this supposedly mythical being, she grinned. She reached up and hooked her fingers around his chin with a breathless, “But maybe this will get my point across for me.”

Nox gave barely a half-yip of surprise before she pulled his head down and kissed him. There was a pause, a stiffening of the merman like he was going to push her away, then one of his arms wrapped around her and pulled her closer, his head tilted just right and Nyx’s mind turned to fuzz because **wow** could this guy kiss. They pulled away for half a breath, then kissed again, and this time Nyx could swear the kiss made her entire body **thrum** with energy. Like the ocean was suddenly inside her, pushing and pulling in her blood like a tide, a storm rumbling deep in her bones while the warmth of sunlight tingled on her skin.

If she’d had her eyes open while kissing Nox, she might have seen the blue rivers of magic coiling possessively around her, whispering under her skin and sinking down to her bones in a silent claim of **_mine_** _,_ ** _mine now and no one else’s_**. But she didn’t, so the feeling of ocean and storm and sunlight continued to be basked in and dismissed in equal measures as a figment of her imagination.

A loud, cackling cheer broken the moment to pieces and Nyx jerked away. Nox shifted his head and actually growled, low and feral with all his sharp teeth exposed. Red Tears just kept whooping and cackling from the water, clapping his hands in delight like it had all been a good show, and while Nyx normally would have tried to find her kukri to stab him, Nox was already diving headlong into the water to tackle the other mer **and** Nyx was a bit distracted by the **human** climbing out of the water with a bemused look on his face. Nyx stared, “ **Axis**?” She sputtered while Red Tears and Nox disappeared under the water in a thrashing tangle of screeching, cackling, and twisting merfolk tails.

Axis, Tredd’s and Luche’s best friend who only occasionally sailed with them and mostly preferred to act as a spy on the conquered mainland of Lucis, didn’t bat an eye at the frothing water and wrestling mermen, just drip-stomped his way over and slapped Nyx hard across the back of her head, “You **idiot**. Your crew is losing their **minds** looking for you.”

“Wha- what are you **doing** here? Did you know those two-?”

“Existed? Lived here? Were **idiots** of the highest degree in general? Yeah.” Nyx kept gaping and Axis sat down on the makeshift carpet with a sigh, “I ran into them about two years ago now. Nox accidentally beached himself in Cape Caem. Got too close to shore during a storm. I found him almost dried out and trying to crawl his way back to the water. I helped him get back to the cove and I’ve been his and Ardyn’s go-to human ever since. I’m **trying** to get them to learn Common, but it’s a work in progress when I only see them every few months.”

Nyx glanced from Axis to the frothing water and back, “So you **knew** merfolk still existed and you didn’t **tell** anyone?”

He shrugged, “As far as I know, they may be the **last** two. No sense risking the Nifs hearing rumors and **actually** dropping that number to zero. Besides, I don’t see them that often.”

Axis narrowed his eyes, “Until **recently** , when they started hanging out in a lake a few miles inland from the cove and Ardyn kept regularly bugging me for soft breads and such. Once I figured out that Ardyn wasn’t the one running errands because Nox was hurt, I figured they’d picked up a stray who needed soft foods and constant care. Maybe even another mer considering they were acting so skittish and protective and wouldn’t let me come down. That was about two weeks ago. I only just managed to talk them into letting me come down here and having a look at whatever Nox has been hiding himself away to care for, and what do I find but the same reckless Ulric Luche’s entire crew has been combing the coastline for, alive and happy as you please, **kissing Nox**.”

Nyx refused to blush, though her skin was still buzzing from the sensation of ocean tides and ozone —and only now did it occur to her that merfolk were **magic** , so maybe their kisses were too, hopefully there were no nasty side-effects—, “Hey, I was trying to thank him. Besides, he kissed back.”

Axis glared, stilled, then leaned close to look at her eyes. A moment later he pulled away and buried his face in his hands, muttering curses. Then he pointed a dire finger her way, “Your eyes are glowing. Nox is possessive as a coeurl over his magic and now your eyes are **glowing with it**.” Axis stood up and shook his head, “You’d better hope that’s just a side-effect of Nox enjoying the kiss and that kissing isn’t a **mating contract** with merfolk.”

Nyx swallowed hard, “It’s a side-effect. Gotta be. …Right?”

Axis pointed wordlessly toward the two mermen, who had apparently finished fighting and were hauling themselves out of the water with angry —or in Ardyn’s case, laughing— chatter, and raised an eyebrow, utterly unimpressed. Nyx blinked. Remembered that merfolk were basically mythical and **highly** magical, and that while no one in the folk tales had ever survived long enough to kiss a mer, Furia sealed marriages with a kiss as well as beads because it was said to be a gifting of hearts in the eyes of the great Tidemother-.

Breathed in and felt the thrumming of something warm and powerful and **other** under her skin that showed no signs of going away. She poked at it mentally, and instantly Nox’s head snapped around to look at her, attentive and bright-eyed, like he’d felt her mental poke as clearly as a physical one even though he was several **yards** away on the cave shore.

Nyx swore, soft and fervent, “Lib is going to **kill me**.”

**Author's Note:**

> Me: Could be working on any number of WIPs, including the Actual Canon Sequel to Nox.
> 
> Also Me: Spam writes this in a few hours instead because I have merfolk and pirates on the brain and there are never enough Mer AUs.
> 
> Also Also Me: starts plotting a sequel to this AU of an AU when I Really Should Be Working On Buckler.
> 
> Anyway, yes, new AU of an AU (for anyone who follows my Tumblr, you'll note this is like- the fourth or fifth Nox spin-off). You should get the gist of what was going on in the background if you've read Nox canon, but as a quick rundown just in case: This is an AU where instead of time-traveling Nox (Post-Plot Noctis) and Reformed Ardyn fall (are yanked by a cackling Leviathan) into another dimension. The catch? The only people with magic in this dimension are merfolk, so the world acclimates itself to Nox's and Ardyn's existence by cheerfully turning them into merfolk. Cue the above Shenanigans when the two find Nyx's piece of driftwood while exploring. They've been here for a while (a little over two years, as hinted at by Axis), so they're mostly acclimated to their new mer instincts, but there are still some ... unknown factors. Like what kissing means in mer culture/instincts >:D.
> 
> Also if anyone is curious, the thing that slammed down onto Nyx's raft and smashed it was Ardyn. He wasn't attacking, he was just trying to haul himself up to say hi and he severely overestimated how well the raft would handle having a hundred pound merman enthusiastically belly flopping on it.
> 
> Also also if anyone is curious, yes Nyx got sick after she passed out and Nox nursed her back to health (Ardyn helped by being the supply runner). Nox did his best to use magic for most of it but she still needed to eat and stuff and she still got cold very easily. Nox didn't want to risk a fire in case he had to leave the cave for any reason, which was why he was cuddling her instead.
> 
> (And yes one of the fleeting memories she has was Nox baby-birding her because she couldn't hold food down any other way)
> 
> I already have a ton of budding worldbuilding for this AU so there's another WIP to add to the list I guess.
> 
> Also I just wrote this today, so there are more than likely grammar/spelling errors in this thing even though I DID give it a quick edit overlook.


End file.
